第五天

学习目的：

掌握ado.net打开sql server数据库的方法。

今天做个非常普通的例子，做一个用户登录框。主要是通过这个练习认识一下sql server数据库的连接方法。和昨天的例子方法基本相同，很容易掌握的。

先建立sql server数据库，库名为aspnetabc，并建立一member新表，建表sql如下：

create table [dbo].[member] (

    [memberid] [int] identity (1, 1) not null ,

    [membername] [nvarchar] (50) collate chinese_prc_ci_as not null ,

    [password] [nvarchar] (50) collate chinese_prc_ci_as not null ,

    [gender] [bit] not null ,

    [birthday] [datetime] null ,

    [email] [nvarchar] (50) collate chinese_prc_ci_as null

) on [primary]

alter table [dbo].[member] with nocheck add

    constraint [pk_member] primary key clustered

    (

        [memberid]

    ) on [primary]

与上一例子差不多，在web.config文件中再增加一行：

<appsettings>

<add key="数据库1" value="ex01.mdb" />

<add key="sqldatabase1" value="data source=localhost;user id=sa;password=sa;initial catalog=aspnetabc;connect timeout=30" />

</appsettings>

在面中添加二个文本框，txtmembername、txtpassword，并设置txtpassword的textmode为password。设置按钮btnlogin。btnlogin的事件代码如下：

        private void btnlogin_click(object sender, system.eventargs e)

        {

            // 先检验输入正确性

            if (txtmembername.text == string.empty || txtmembername.text.trim() == "")

            {

                response.write("<script language=javascript>alert('帐号不能为空')</script>");

                return;

            }

            if (txtpassword.text == string.empty || txtpassword.text.trim() == "")

                response.write("<script language=javascript>alert('没有输入密码')</script>");

            string strconnection = configurationsettings.appsettings["sqldatabase1"];

            string sqlmember = "select membername ,[password] from member "

                + " where membername = '" + txtmembername.text.trim() + "'"

                + " and [password] = '" + txtpassword.text.trim() + "'";

            // 连接sqlserver数据库

            sqlconnection conn = new sqlconnection(strconnection);

            // 建立sqlcommand

            sqlcommand cmd = conn.createcommand();

            cmd.commandtext = sqlmember;

            conn.open();

            // 建立datareader

            sqldatareader dr = cmd.executereader();

            // 判断datareader是否为空记录

            if (dr.hasrows)

                response.write("<script language=javascript>alert('" + txtmembername.text + "欢迎你！')</script>");

            else

                response.write("<script language=javascript>alert('找不到该会员，或密码错误。')</script>");

            // 千万不要忘记关闭datareader

            dr.close();

            conn.close();

        }

好了，一个非常简单的登录框做好了。当然在实际程序中还应加入跳转等，这个就留给你做了。